/* Produced by texiweb from libavl.w. */

/* libavl - library for manipulation of binary trees.
   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
   Foundation, Inc.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 3 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301 USA.
*/

#ifndef AVL_H
#define AVL_H 1

#include <stddef.h>

/* Function types. */
typedef int avl_comparison_func (const void *avl_a, const void *avl_b,
				 void *avl_param);
typedef void avl_item_func (void *avl_item, void *avl_param);
typedef void *avl_copy_func (void *avl_item, void *avl_param);

#ifndef LIBAVL_ALLOCATOR
#define LIBAVL_ALLOCATOR
/* Memory allocator. */
struct libavl_allocator
{
	void *(*libavl_malloc) (struct libavl_allocator *, size_t libavl_size);
	void (*libavl_free) (struct libavl_allocator *, void *libavl_block);
};
#endif

#ifdef __cplusplus
extern "C" {
#endif

/* Default memory allocator. */
extern struct libavl_allocator avl_allocator_default;
void *avl_malloc (struct libavl_allocator *, size_t);
void avl_free (struct libavl_allocator *, void *);

/* Maximum AVL tree height. */
#ifndef AVL_MAX_HEIGHT
#define AVL_MAX_HEIGHT 92
#endif

/* Tree data structure. */
struct avl_table
{
	struct avl_node *avl_root;	    /* Tree's root. */
	avl_comparison_func *avl_compare;   /* Comparison function. */
	void *avl_param;		    /* Extra argument to |avl_compare|. */
	struct libavl_allocator *avl_alloc; /* Memory allocator. */
	size_t avl_count;		    /* Number of items in tree. */
	unsigned long avl_generation;	    /* Generation number. */
};

/* An AVL tree node. */
struct avl_node
{
	struct avl_node *avl_link[2];  /* Subtrees. */
	void *avl_data;		       /* Pointer to data. */
	signed char avl_balance;       /* Balance factor. */
};

/* AVL traverser structure. */
struct avl_traverser
{
	struct avl_table *avl_table;	    /* Tree being traversed. */
	struct avl_node *avl_node;	    /* Current node in tree. */
	struct avl_node *avl_stack[AVL_MAX_HEIGHT];
	/* All the nodes above |avl_node|. */
	size_t avl_height;		    /* Number of nodes in |avl_parent|. */
	unsigned long avl_generation;	    /* Generation number. */
};

/* Table functions. */
struct avl_table *avl_create (avl_comparison_func *, void *,
			      struct libavl_allocator *);
struct avl_table *avl_copy (const struct avl_table *, avl_copy_func *,
			    avl_item_func *, struct libavl_allocator *);
void avl_destroy (struct avl_table *, avl_item_func *);
void **avl_probe (struct avl_table *, void *);
void *avl_insert (struct avl_table *, void *);
void *avl_replace (struct avl_table *, void *);
void *avl_delete (struct avl_table *, const void *);
void *avl_find (const struct avl_table *, const void *);
void avl_assert_insert (struct avl_table *, void *);
void *avl_assert_delete (struct avl_table *, void *);

#define avl_count(table) ((size_t) (table)->avl_count)

/* Table traverser functions. */
void avl_t_init (struct avl_traverser *, struct avl_table *);
void *avl_t_first (struct avl_traverser *, struct avl_table *);
void *avl_t_last (struct avl_traverser *, struct avl_table *);
void *avl_t_find (struct avl_traverser *, struct avl_table *, void *);
void *avl_t_insert (struct avl_traverser *, struct avl_table *, void *);
void *avl_t_copy (struct avl_traverser *, const struct avl_traverser *);
void *avl_t_next (struct avl_traverser *);
void *avl_t_prev (struct avl_traverser *);
void *avl_t_cur (struct avl_traverser *);
void *avl_t_replace (struct avl_traverser *, void *);

#ifdef __cplusplus
}
#endif

#endif /* avl.h */
